using System.Diagnostics;
using System.Globalization;
using System.Text;
using Nub.Lang.Frontend.Parsing;
using Nub.Lang.Frontend.Parsing.Definitions;
using Nub.Lang.Frontend.Parsing.Expressions;
using Nub.Lang.Frontend.Parsing.Statements;
using Nub.Lang.Frontend.Typing;

namespace Nub.Lang.Frontend.Generation;

public class Generator
{
    private const string OutOfBoundsMessage = "Index is out of bounds\\n";

    private List<SourceFile> _sourceFiles = [];
    private StringBuilder _builder = new();
    private Dictionary<string, Variable> _variables = [];
    private List<string> _strings = [];
    private Stack<string> _breakLabels = [];
    private Stack<string> _continueLabels = [];
    private int _variableIndex;
    private int _labelIndex;
    private int _funcIndex;
    private bool _codeIsReachable = true;
    private Dictionary<IFuncSignature, string> _funcNames = [];

    public string Generate(List<SourceFile> sourceFiles)
    {
        _sourceFiles = sourceFiles;
        _builder = new StringBuilder();
        _variables = new Dictionary<string, Variable>();
        _strings = [];
        _funcNames = [];
        _breakLabels = [];
        _continueLabels = [];
        _variableIndex = 0;
        _funcIndex = 0;
        _labelIndex = 0;
        _codeIsReachable = true;

        foreach (var structDef in _sourceFiles.SelectMany(f => f.Definitions).OfType<StructDefinitionNode>())
        {
            GenerateStructDefinition(structDef);
            _builder.AppendLine();
        }

        foreach (var funcSignature in _sourceFiles.SelectMany(f => f.Definitions).OfType<IFuncSignature>())
        {
            switch (funcSignature)
            {
                case ExternFuncDefinitionNode externFuncDefinitionNode:
                    _funcNames[funcSignature] = externFuncDefinitionNode.Name;
                    break;
                case LocalFuncDefinitionNode localFuncDefinitionNode:
                    if (localFuncDefinitionNode.Exported)
                    {
                        _funcNames[funcSignature] = localFuncDefinitionNode.Name;
                    }
                    else
                    {
                        var funcName = GenFuncName();
                        _funcNames[funcSignature] = funcName;
                    }

                    break;
                default:
                    throw new ArgumentOutOfRangeException(nameof(funcSignature));
            }
        }

        foreach (var funcDef in _sourceFiles.SelectMany(f => f.Definitions).OfType<LocalFuncDefinitionNode>())
        {
            GenerateFuncDefinition(funcDef);
            _builder.AppendLine();
        }

        _builder.AppendLine($"data $oob_message = {{ b \"{OutOfBoundsMessage}\" }}");

        for (var i = 0; i < _strings.Count; i++)
        {
            var str = _strings[i];
            _builder.AppendLine($"data $str{i + 1} = {{ b \"{str}\", b 0 }}");
        }

        return _builder.ToString();
    }

    private static string SQT(NubType type)
    {
        switch (type)
        {
            case NubPrimitiveType primitiveType:
            {
                switch (primitiveType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.String:
                    case PrimitiveTypeKind.Any:
                        return "l";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                    case PrimitiveTypeKind.Bool:
                        return "w";
                    case PrimitiveTypeKind.F64:
                        return "d";
                    case PrimitiveTypeKind.F32:
                        return "s";
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }
            case NubStructType:
            case NubPointerType:
            case NubArrayType:
            {
                return "l";
            }
            default:
            {
                throw new NotImplementedException();
            }
        }
    }

    private static string EQT(NubType type)
    {
        switch (type)
        {
            case NubPrimitiveType primitiveType:
            {
                switch (primitiveType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.String:
                        return "l";
                    case PrimitiveTypeKind.Any:
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                        return "w";
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                        return "h";
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return "b";
                    case PrimitiveTypeKind.Bool:
                    case PrimitiveTypeKind.F64:
                        return "d";
                    case PrimitiveTypeKind.F32:
                        return "s";
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }
            case NubStructType nubCustomType:
            {
                return ":" + nubCustomType.Name;
            }
            case NubPointerType:
            case NubArrayType:
            {
                return "l";
            }
            default:
            {
                throw new NotImplementedException();
            }
        }
    }

    private static string FQT(NubType type)
    {
        switch (type)
        {
            case NubPrimitiveType primitiveType:
            {
                switch (primitiveType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.String:
                    case PrimitiveTypeKind.Any:
                        return "l";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                        return "w";
                    case PrimitiveTypeKind.I16:
                        return "sh";
                    case PrimitiveTypeKind.U16:
                        return "uh";
                    case PrimitiveTypeKind.I8:
                        return "sb";
                    case PrimitiveTypeKind.U8:
                        return "ub";
                    case PrimitiveTypeKind.Bool:
                        return "b";
                    case PrimitiveTypeKind.F64:
                        return "d";
                    case PrimitiveTypeKind.F32:
                        return "s";
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }
            case NubStructType nubCustomType:
            {
                return ":" + nubCustomType.Name;
            }
            case NubPointerType:
            case NubArrayType:
            {
                return "l";
            }
            default:
            {
                throw new NotImplementedException();
            }
        }
    }

    private int QbeTypeSize(NubType type)
    {
        switch (type)
        {
            case NubPrimitiveType primitiveType:
            {
                switch (primitiveType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.String:
                    case PrimitiveTypeKind.Any:
                        return 8;
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                        return 4;
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                        return 2;
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                    case PrimitiveTypeKind.Bool:
                        return 1;
                    case PrimitiveTypeKind.F64:
                        return 8;
                    case PrimitiveTypeKind.F32:
                        return 4;
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }
            case NubStructType nubStructType:
            {
                var definition = LookupStructDefinition(nubStructType.Namespace, nubStructType.Name);
                return definition.Fields.Sum(f => QbeTypeSize(f.Type));
            }
            case NubPointerType:
            case NubArrayType:
            {
                return 8;
            }
            default:
            {
                throw new NotImplementedException();
            }
        }
    }

    private bool IsLargeType(NubType type)
    {
        return QbeTypeSize(type) > 8;
    }

    private void GenerateFuncDefinition(LocalFuncDefinitionNode node)
    {
        _variables.Clear();

        if (node.Exported)
        {
            _builder.Append("export ");
        }

        _builder.Append("function ");
        if (node.ReturnType.HasValue)
        {
            _builder.Append($"{FQT(node.ReturnType.Value)} ");
        }
        else if (!node.ReturnType.HasValue && node.Name == "main")
        {
            _builder.Append("l ");
        }

        _builder.Append('$');
        _builder.Append(_funcNames[node]);

        var parameterStrings = node.Parameters.Select(parameter => parameter.Variadic ? "..." : $"{FQT(parameter.Type)} %{parameter.Name}");

        _builder.AppendLine($"({string.Join(", ", parameterStrings)}) {{");
        _builder.AppendLine("@start");

        foreach (var parameter in node.Parameters)
        {
            var parameterName = parameter.Name;

            switch (FQT(parameter.Type))
            {
                case "sb":
                    parameterName = GenVarName();
                    _builder.AppendLine($"    %{parameterName} =w extsb %{parameter.Name}");
                    break;
                case "ub":
                    parameterName = GenVarName();
                    _builder.AppendLine($"    %{parameterName} =w extub %{parameter.Name}");
                    break;
                case "sh":
                    parameterName = GenVarName();
                    _builder.AppendLine($"    %{parameterName} =w extsh %{parameter.Name}");
                    break;
                case "uh":
                    parameterName = GenVarName();
                    _builder.AppendLine($"    %{parameterName} =w extuh %{parameter.Name}");
                    break;
            }

            var pointerName = GenVarName();
            _builder.AppendLine($"    %{pointerName} ={SQT(parameter.Type)} alloc8 {QbeTypeSize(parameter.Type)}");
            _builder.AppendLine($"    storel %{parameterName}, %{pointerName}");


            _variables[parameter.Name] = new Variable
            {
                Pointer = $"%{pointerName}",
                Type = parameter.Type
            };
        }

        GenerateBlock(node.Body);

        if (node.Body.Statements.LastOrDefault() is not ReturnNode)
        {
            if (!node.ReturnType.HasValue && node.Name == "main")
            {
                _builder.AppendLine();
                _builder.AppendLine("    # Implicit return for main");
                _builder.AppendLine("    ret 0");
            }
            else if (!node.ReturnType.HasValue)
            {
                _builder.AppendLine();
                _builder.AppendLine("    # Implicit return");
                _builder.AppendLine("    ret");
            }
        }

        _builder.AppendLine("}");
    }

    private void GenerateStructDefinition(StructDefinitionNode structDefinition)
    {
        var fields = structDefinition.Fields.Select(f => EQT(f.Type));
        _builder.AppendLine($"type :{structDefinition.Name} = {{ {string.Join(", ", fields)} }}");
    }

    private void GenerateStatement(StatementNode statement)
    {
        switch (statement)
        {
            case ArrayIndexAssignmentNode arrayIndexAssignment:
                throw new NotImplementedException();
                break;
            case BreakNode:
                GenerateBreak();
                break;
            case ContinueNode:
                GenerateContinue();
                break;
            case IfNode ifStatement:
                GenerateIf(ifStatement);
                break;
            case MemberAssignmentNode memberAssignment:
                GenerateMemberAssignment(memberAssignment);
                break;
            case ReturnNode @return:
                GenerateReturn(@return);
                break;
            case StatementExpressionNode statementExpression:
                GenerateExpression(statementExpression.Expression);
                break;
            case VariableAssignmentNode variableAssignment:
                GenerateVariableAssignment(variableAssignment);
                break;
            case VariableDeclarationNode variableDeclaration:
                GenerateVariableDeclaration(variableDeclaration);
                break;
            case WhileNode whileStatement:
                GenerateWhile(whileStatement);
                break;
            default:
                throw new ArgumentOutOfRangeException(nameof(statement));
        }
    }

    private void GenerateBlock(BlockNode block)
    {
        foreach (var statement in block.Statements.Where(_ => _codeIsReachable))
        {
            GenerateStatement(statement);
        }

        _codeIsReachable = true;
    }

    private void GenerateBreak()
    {
        _builder.AppendLine($"    jmp @{_breakLabels.Peek()}");
        _codeIsReachable = false;
    }

    private void GenerateContinue()
    {
        _builder.AppendLine($"    jmp @{_continueLabels.Peek()}");
        _codeIsReachable = false;
    }

    private void GenerateIf(IfNode ifStatement)
    {
        var trueLabel = GenLabelName();
        var falseLabel = GenLabelName();
        var endLabel = GenLabelName();

        var result = GenerateExpression(ifStatement.Condition);
        _builder.AppendLine($"    jnz {result}, @{trueLabel}, @{falseLabel}");
        _builder.AppendLine($"@{trueLabel}");
        GenerateBlock(ifStatement.Body);
        _builder.AppendLine($"    jmp @{endLabel}");
        _builder.AppendLine($"@{falseLabel}");
        if (ifStatement.Else.HasValue)
        {
            ifStatement.Else.Value.Match
            (
                GenerateIf,
                GenerateBlock
            );
        }

        _builder.AppendLine($"@{endLabel}");
    }

    private void GenerateMemberAssignment(MemberAssignmentNode memberAssignment)
    {
        var structType = memberAssignment.MemberAccess.Expression.Type as NubStructType;
        Debug.Assert(structType != null);
        
        var structDefinition = LookupStructDefinition(structType.Namespace, structType.Name);
        var offset = LookupMemberOffset(structDefinition, memberAssignment.MemberAccess.Member);

        var item = GenerateExpression(memberAssignment.MemberAccess.Expression);
        var offsetName = GenVarName();
        
        _builder.AppendLine($"    %{offsetName} =l add {item}, {offset}");

        var value = GenerateExpression(memberAssignment.Value);

        throw new NotImplementedException();
    }

    private void GenerateReturn(ReturnNode @return)
    {
        if (@return.Value.HasValue)
        {
            var result = GenerateExpression(@return.Value.Value);
            _builder.AppendLine($"    ret {result}");
        }
        else
        {
            _builder.AppendLine("    ret");
        }
    }

    private void GenerateVariableAssignment(VariableAssignmentNode variableAssignment)
    {
        var result = GenerateExpression(variableAssignment.Value);
        _builder.AppendLine($"    storel {result}, {_variables[variableAssignment.Identifier.Identifier].Pointer}");
    }

    private void GenerateVariableDeclaration(VariableDeclarationNode variableDeclaration)
    {
        var pointerName = GenVarName();

        var type = variableDeclaration.ExplicitType.Value ?? variableDeclaration.Value.Value?.Type!;

        _builder.AppendLine($"    %{pointerName} ={SQT(type)} alloc8 {QbeTypeSize(type)}");

        if (variableDeclaration.Value.HasValue)
        {
            var result = GenerateExpression(variableDeclaration.Value.Value);
            _builder.AppendLine($"    storel {result}, %{pointerName}");
        }
        else
        {
            _builder.AppendLine($"    storel 0, %{pointerName}");
        }

        _variables[variableDeclaration.Name] = new Variable
        {
            Pointer = $"%{pointerName}",
            Type = type
        };
    }

    private void GenerateWhile(WhileNode whileStatement)
    {
        var conditionLabel = GenLabelName();
        var iterationLabel = GenLabelName();
        var endLabel = GenLabelName();

        _breakLabels.Push(endLabel);
        _continueLabels.Push(conditionLabel);

        _builder.AppendLine($"    jmp @{conditionLabel}");
        _builder.AppendLine($"@{iterationLabel}");
        GenerateBlock(whileStatement.Body);
        _builder.AppendLine($"@{conditionLabel}");
        var result = GenerateExpression(whileStatement.Condition);
        _builder.AppendLine($"    jnz {result}, @{iterationLabel}, @{endLabel}");
        _builder.AppendLine($"@{endLabel}");

        _continueLabels.Pop();
        _breakLabels.Pop();
    }

    private string GenerateExpression(ExpressionNode expression)
    {
        return expression switch
        {
            AddressOfNode addressOf => GenerateAddressOf(addressOf),
            ArrayIndexAccessNode arrayIndex => GenerateArrayIndex(arrayIndex),
            ArrayInitializerNode arrayInitializer => GenerateArrayInitializer(arrayInitializer),
            BinaryExpressionNode binaryExpression => GenerateBinaryExpression(binaryExpression),
            CastNode cast => GenerateCast(cast),
            DereferenceNode dereference => GenerateDereference(dereference),
            FuncCallNode funcCallExpression => GenerateFuncCall(funcCallExpression),
            IdentifierNode identifier => GenerateIdentifier(identifier),
            LiteralNode literal => GenerateLiteral(literal),
            StructInitializerNode structInitializer => GenerateStructInitializer(structInitializer),
            UnaryExpressionNode unaryExpression => GenerateUnaryExpression(unaryExpression),
            MemberAccessNode memberAccess => GenerateMemberAccess(memberAccess),
            _ => throw new ArgumentOutOfRangeException(nameof(expression))
        };
    }

    private string GenerateArrayIndex(ArrayIndexAccessNode arrayIndexAccess)
    {
        var array = GenerateExpression(arrayIndexAccess.Array);
        var index = GenerateExpression(arrayIndexAccess.Index);

        var arrayBaseType = ((NubArrayType)arrayIndexAccess.Array.Type).BaseType;

        var countName = GenVarName();
        _builder.AppendLine($"    %{countName} =l loadl {array}");

        var isNegativeName = GenVarName();
        _builder.AppendLine($"    %{isNegativeName} =w csltl {index}, 0");

        var isOobName = GenVarName();
        _builder.AppendLine($"    %{isOobName} =w csgel {index}, %{countName}");

        var anyOobName = GenVarName();
        _builder.AppendLine($"    %{anyOobName} =w or %{isNegativeName}, %{isOobName}");

        var oobLabel = GenLabelName();
        var notOobLabel = GenLabelName();
        _builder.AppendLine($"    jnz %{anyOobName}, @{oobLabel}, @{notOobLabel}");

        _builder.AppendLine($"@{oobLabel}");
        _builder.AppendLine($"    call $nub_panic(l $oob_message, l {OutOfBoundsMessage.Length})");

        _builder.AppendLine($"@{notOobLabel}");

        // Calculate element address
        var firstItemPointerName = GenVarName();
        _builder.AppendLine($"    %{firstItemPointerName} =l add {array}, 8");
        var offsetPointerName = GenVarName();
        _builder.AppendLine($"    %{offsetPointerName} =l mul {index}, {QbeTypeSize(arrayBaseType)}");
        var resultPointerName = GenVarName();
        _builder.AppendLine($"    %{resultPointerName} =l add %{firstItemPointerName}, %{offsetPointerName}");

        // Load the value
        var outputName = GenVarName();
        _builder.AppendLine($"    %{outputName} ={SQT(arrayBaseType)} load{SQT(arrayBaseType)} %{resultPointerName}");
        return $"%{outputName}";
    }

    private string GenerateArrayInitializer(ArrayInitializerNode arrayInitializer)
    {
        var capacity = GenerateExpression(arrayInitializer.Capacity);
        var capacityInBytes = GenVarName();
        _builder.AppendLine($"    %{capacityInBytes} =l mul {capacity}, {QbeTypeSize(arrayInitializer.ItemType)}");
        var totalArraySize = GenVarName();
        _builder.AppendLine($"    %{totalArraySize} =l add %{capacityInBytes}, 8");
        var outputName = GenVarName();
        _builder.AppendLine($"    %{outputName} =l alloc8 %{totalArraySize}");
        _builder.AppendLine($"    storel {capacity}, %{outputName}");

        var dataPtr = GenVarName();
        _builder.AppendLine($"    %{dataPtr} =l add %{outputName}, 8");
        _builder.AppendLine($"    call $nub_memset(l %{dataPtr}, w 0, l %{capacityInBytes})");

        return $"%{outputName}";
    }

    private string GenerateDereference(DereferenceNode dereference)
    {
        var result = GenerateExpression(dereference.Expression);
        var outputName = GenVarName();
        _builder.AppendLine($"    %{outputName} ={SQT(dereference.Type)} load{SQT(dereference.Type)} {result}");
        return $"%{outputName}";
    }

    private string GenerateAddressOf(AddressOfNode addressOf)
    {
        var result = GenerateExpression(addressOf.Expression);
        var outputName = GenVarName();
        switch (addressOf.Expression.Type)
        {
            case NubPointerType:
            case NubStructType:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.String }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.I64 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.F64 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.U64 }:
                _builder.AppendLine($"    %{outputName} =l alloc8 8");
                _builder.AppendLine($"    storel {result}, %{outputName}");
                return $"%{outputName}";
            case NubPrimitiveType { Kind: PrimitiveTypeKind.I32 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.U32 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.I16 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.U16 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.I8 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.U8 }:
            case NubPrimitiveType { Kind: PrimitiveTypeKind.F32 }:
                _builder.AppendLine($"    %{outputName} =l alloc8 4");
                _builder.AppendLine($"    storew {result}, %{outputName}");
                return $"%{outputName}";
            default:
                throw new ArgumentOutOfRangeException();
        }
    }

    private string GenerateBinaryExpression(BinaryExpressionNode binaryExpression)
    {
        var left = GenerateExpression(binaryExpression.Left);
        var right = GenerateExpression(binaryExpression.Right);
        var outputName = GenVarName();

        switch (binaryExpression.Operator)
        {
            case BinaryExpressionOperator.Equal:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =w ceql {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w ceqw {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.String))
                {
                    _builder.AppendLine($"    %{outputName} =w call $nub_strcmp(l {left}, l {right})");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.Bool))
                {
                    _builder.AppendLine($"    %{outputName} =w ceqw {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.NotEqual:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =w cnel {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w cnew {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.String))
                {
                    _builder.AppendLine($"    %{outputName} =w call $nub_strcmp(l {left}, l {right})");
                    _builder.AppendLine($"    %{outputName} =w xor %{outputName}, 1");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.Bool))
                {
                    _builder.AppendLine($"    %{outputName} =w cnew {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.GreaterThan:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =w csgtl {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w csgtw {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.Bool))
                {
                    _builder.AppendLine($"    %{outputName} =w csgtw {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.GreaterThanOrEqual:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =w csgel {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w csgew {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.Bool))
                {
                    _builder.AppendLine($"    %{outputName} =w csgew {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.LessThan:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =w csltl {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w csltw {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.Bool))
                {
                    _builder.AppendLine($"    %{outputName} =w csltw {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.LessThanOrEqual:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =w cslel {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w cslew {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.Bool))
                {
                    _builder.AppendLine($"    %{outputName} =w cslew {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.Plus:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =l add {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w add {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.Minus:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =l sub {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w sub {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.Multiply:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =l mul {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w mul {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            case BinaryExpressionOperator.Divide:
            {
                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I64))
                {
                    _builder.AppendLine($"    %{outputName} =l div {left}, {right}");
                    return $"%{outputName}";
                }

                if (binaryExpression.Left.Type.Equals(NubPrimitiveType.I32))
                {
                    _builder.AppendLine($"    %{outputName} =w div {left}, {right}");
                    return $"%{outputName}";
                }

                break;
            }
            default:
            {
                throw new ArgumentOutOfRangeException();
            }
        }

        throw new NotSupportedException($"Binary operator {binaryExpression.Operator} for types {binaryExpression.Left.Type} and {binaryExpression.Right.Type} not supported");
    }

    private string GenerateCast(CastNode cast)
    {
        var input = GenerateExpression(cast.Expression);
        var outputType = cast.TargetType;
        var inputType = cast.Expression.Type;

        if (inputType.Equals(outputType))
        {
            return input;
        }

        if (outputType is not NubPrimitiveType primitiveOutputType || inputType is not NubPrimitiveType primitiveInputType)
        {
            throw new NotSupportedException("Casting is only supported for primitive types");
        }

        var outputName = GenVarName();

        switch (primitiveInputType.Kind)
        {
            case PrimitiveTypeKind.I64:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.Any:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                        _builder.AppendLine($"    %{outputName} =d sltof {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.F32:
                        _builder.AppendLine($"    %{outputName} =s sltof {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_i64_to_string(l {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.I32:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l extsw {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extsw {input}");
                        _builder.AppendLine($"    %{outputName} =d sltof %{extName}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.F32:
                        _builder.AppendLine($"    %{outputName} =s swtof {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_i32_to_string(w {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.Any:
                        var extAnyName = GenVarName();
                        _builder.AppendLine($"    %{extAnyName} =l extsw {input}");
                        return $"%{extAnyName}";
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.I16:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l extsh {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                        _builder.AppendLine($"    %{outputName} =w extsh {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extsh {input}");
                        _builder.AppendLine($"    %{outputName} =d sltof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.F32:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extsh {input}");
                        _builder.AppendLine($"    %{outputName} =s swtof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.String:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extsh {input}");
                        _builder.AppendLine($"    %{outputName} =l call $nub_i32_to_string(w %{extName})");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.Any:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extsh {input}");
                        return $"%{extName}";
                    }
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.I8:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l extsb {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                        _builder.AppendLine($"    %{outputName} =w extsb {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extsb {input}");
                        _builder.AppendLine($"    %{outputName} =d sltof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.F32:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extsb {input}");
                        _builder.AppendLine($"    %{outputName} =s swtof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.String:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extsb {input}");
                        _builder.AppendLine($"    %{outputName} =l call $nub_i32_to_string(w %{extName})");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.Any:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extsb {input}");
                        return $"%{extName}";
                    }
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.U64:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                        _builder.AppendLine($"    %{outputName} =d ultof {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.F32:
                        _builder.AppendLine($"    %{outputName} =s ultof {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_u64_to_string(l {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.Any:
                        return input;
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.U32:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l extuw {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extuw {input}");
                        _builder.AppendLine($"    %{outputName} =d ultof %{extName}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.F32:
                        _builder.AppendLine($"    %{outputName} =s uwtof {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_u32_to_string(w {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.Any:
                        var extAnyName = GenVarName();
                        _builder.AppendLine($"    %{extAnyName} =l extuw {input}");
                        return $"%{extAnyName}";
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.U16:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l extuh {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                        _builder.AppendLine($"    %{outputName} =w extuh {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extuh {input}");
                        _builder.AppendLine($"    %{outputName} =d ultof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.F32:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extuh {input}");
                        _builder.AppendLine($"    %{outputName} =s uwtof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.String:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extuh {input}");
                        _builder.AppendLine($"    %{outputName} =l call $nub_u32_to_string(w %{extName})");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.Any:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extuh {input}");
                        return $"%{extName}";
                    }
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.U8:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l extub {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.U16:
                        _builder.AppendLine($"    %{outputName} =w extub {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U8:
                        return input;
                    case PrimitiveTypeKind.F64:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extub {input}");
                        _builder.AppendLine($"    %{outputName} =d ultof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.F32:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extub {input}");
                        _builder.AppendLine($"    %{outputName} =s uwtof %{extName}");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.String:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =w extub {input}");
                        _builder.AppendLine($"    %{outputName} =l call $nub_u32_to_string(w %{extName})");
                        return $"%{outputName}";
                    }
                    case PrimitiveTypeKind.Any:
                    {
                        var extName = GenVarName();
                        _builder.AppendLine($"    %{extName} =l extub {input}");
                        return $"%{extName}";
                    }
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.F64:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.F64:
                    case PrimitiveTypeKind.Any:
                        return input;
                    case PrimitiveTypeKind.F32:
                        _builder.AppendLine($"    %{outputName} =s dtos {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I64:
                        _builder.AppendLine($"    %{outputName} =l dtosi {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.I8:
                        _builder.AppendLine($"    %{outputName} =w dtosi {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l dtoui {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.U8:
                        _builder.AppendLine($"    %{outputName} =w dtoui {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_f64_to_string(d {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.F32:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.F64:
                        _builder.AppendLine($"    %{outputName} =d stod {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.F32:
                        return input;
                    case PrimitiveTypeKind.I64:
                        _builder.AppendLine($"    %{outputName} =l stosi {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.I8:
                        _builder.AppendLine($"    %{outputName} =w stosi {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.U64:
                        _builder.AppendLine($"    %{outputName} =l stoui {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.U8:
                        _builder.AppendLine($"    %{outputName} =w stoui {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_f32_to_string(s {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.Any:
                        throw new NotImplementedException();
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.Bool:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.Bool:
                        return input;
                    case PrimitiveTypeKind.Any:
                        _builder.AppendLine($"    %{outputName} =l extsw {input}");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.String:
                        _builder.AppendLine($"    %{outputName} =l call $nub_bool_to_string(s {input})");
                        return $"%{outputName}";
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.U8:
                    case PrimitiveTypeKind.F64:
                    case PrimitiveTypeKind.F32:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.String:
                switch (primitiveOutputType.Kind)
                {
                    case PrimitiveTypeKind.String:
                    case PrimitiveTypeKind.Any:
                        return input;
                    case PrimitiveTypeKind.I64:
                    case PrimitiveTypeKind.I32:
                    case PrimitiveTypeKind.I16:
                    case PrimitiveTypeKind.I8:
                    case PrimitiveTypeKind.U64:
                    case PrimitiveTypeKind.U32:
                    case PrimitiveTypeKind.U16:
                    case PrimitiveTypeKind.U8:
                    case PrimitiveTypeKind.F64:
                    case PrimitiveTypeKind.F32:
                    case PrimitiveTypeKind.Bool:
                    default:
                        throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
                }
            case PrimitiveTypeKind.Any:
                return input;
            default:
                throw new NotSupportedException($"Casting from {primitiveInputType.Kind} to {primitiveOutputType.Kind} is not supported");
        }
    }

    private string GenerateIdentifier(IdentifierNode identifier)
    {
        var variable = _variables[identifier.Identifier];
        var outputName = GenVarName();
        _builder.AppendLine($"    %{outputName} ={SQT(identifier.Type)} load{SQT(identifier.Type)} {variable.Pointer}");
        return $"%{outputName}";
    }

    private string GenerateLiteral(LiteralNode literal)
    {
        if (literal.LiteralType.Equals(NubPrimitiveType.String))
        {
            _strings.Add(literal.Literal);
            return $"$str{_strings.Count}";
        }

        if (literal.LiteralType.Equals(NubPrimitiveType.I64))
        {
            return literal.Literal;
        }

        if (literal.LiteralType.Equals(NubPrimitiveType.F64))
        {
            var value = double.Parse(literal.Literal, CultureInfo.InvariantCulture);
            var bits = BitConverter.DoubleToInt64Bits(value);
            return bits.ToString();
        }

        if (literal.LiteralType.Equals(NubPrimitiveType.Bool))
        {
            return bool.Parse(literal.Literal) ? "1" : "0";
        }

        throw new NotSupportedException($"Literal {literal.LiteralType} is not supported");
    }

    private string GenerateStructInitializer(StructInitializerNode structInitializer)
    {
        var structDefinition = LookupStructDefinition(structInitializer.StructType.Namespace, structInitializer.StructType.Name);
        
        var structVar = GenVarName();
        var size = structDefinition.Fields.Sum(x => QbeTypeSize(x.Type));
        _builder.AppendLine($"    %{structVar} =l alloc8 {size}");

        foreach (var field in structDefinition.Fields)
        {
            var offset = LookupMemberOffset(structDefinition, field.Name);

            if (structInitializer.Initializers.TryGetValue(field.Name, out var fieldValue))
            {
                var var = GenerateExpression(fieldValue);
                var offsetName = GenVarName();
                _builder.AppendLine($"    %{offsetName} =l add %{structVar}, {offset}");

                if (IsLargeType(field.Type))
                {
                    _builder.AppendLine($"    blit {var}, %{offsetName}, {QbeTypeSize(field.Type)}");
                }
                else
                {
                    _builder.AppendLine($"    store{SQT(field.Type)} {var}, %{offsetName}");
                }
            }
            else if (field.Value.HasValue)
            {
                var var = GenerateExpression(field.Value.Value);
                var offsetName = GenVarName();
                _builder.AppendLine($"    %{offsetName} =l add %{structVar}, {offset}");

                if (IsLargeType(field.Type))
                {
                    _builder.AppendLine($"    blit {var}, %{offsetName}, {QbeTypeSize(field.Type)}");
                }
                else
                {
                    _builder.AppendLine($"    store{SQT(field.Type)} {var}, %{offsetName}");
                }
            }
            else
            {
                Debug.Assert(false);
            }
        }

        return $"%{structVar}";
    }

    private string GenerateUnaryExpression(UnaryExpressionNode unaryExpression)
    {
        var operand = GenerateExpression(unaryExpression.Operand);
        var outputName = GenVarName();

        switch (unaryExpression.Operator)
        {
            case UnaryExpressionOperator.Negate:
            {
                switch (unaryExpression.Operand.Type)
                {
                    case NubPrimitiveType { Kind: PrimitiveTypeKind.I64 }:
                        _builder.AppendLine($"    %{outputName} =l neg {operand}");
                        return $"%{outputName}";
                    case NubPrimitiveType { Kind: PrimitiveTypeKind.I32 or PrimitiveTypeKind.I16 or PrimitiveTypeKind.I8 }:
                        _builder.AppendLine($"    %{outputName} =w neg {operand}");
                        return $"%{outputName}";
                    case NubPrimitiveType { Kind: PrimitiveTypeKind.F64 }:
                        _builder.AppendLine($"    %{outputName} =d neg {operand}");
                        return $"%{outputName}";
                    case NubPrimitiveType { Kind: PrimitiveTypeKind.F32 }:
                        _builder.AppendLine($"    %{outputName} =s neg {operand}");
                        return $"%{outputName}";
                }

                break;
            }
            case UnaryExpressionOperator.Invert:
            {
                switch (unaryExpression.Operand.Type)
                {
                    case NubPrimitiveType { Kind: PrimitiveTypeKind.Bool }:
                        _builder.AppendLine($"    %{outputName} =w xor {operand}, 1");
                        return $"%{outputName}";
                }

                break;
            }
            default:
            {
                throw new ArgumentOutOfRangeException();
            }
        }

        throw new NotSupportedException($"Unary operator {unaryExpression.Operator} for type {unaryExpression.Operand.Type} not supported");
    }

    private string GenerateMemberAccess(MemberAccessNode memberAccess)
    {
        var item = GenerateExpression(memberAccess.Expression);

        switch (memberAccess.Expression.Type)
        {
            case NubArrayType:
            {
                if (memberAccess.Member == "count")
                {
                    var outputName = GenVarName();
                    _builder.AppendLine($"    %{outputName} =l loadl {item}");
                    return $"%{outputName}";
                }

                throw new ArgumentOutOfRangeException(nameof(memberAccess.Member));
            }
            case NubStructType structType:
            {
                var structDefinition = LookupStructDefinition(structType.Namespace, structType.Name);
                var offset = LookupMemberOffset(structDefinition, memberAccess.Member);

                var offsetName = GenVarName();
                _builder.AppendLine($"    %{offsetName} =l add {item}, {offset}");

                if (IsLargeType(memberAccess.Type))
                {
                    return $"%{offsetName}";
                }
                else
                {
                    var outputName = GenVarName();
                    _builder.AppendLine($"    %{outputName} ={SQT(memberAccess.Type)} load{SQT(memberAccess.Type)} %{offsetName}");

                    return $"%{outputName}";
                }
            }
            default:
            {
                throw new ArgumentOutOfRangeException(nameof(memberAccess.Expression.Type));
            }
        }
    }

    private string GenerateFuncCall(FuncCallNode funcCall)
    {
        var outputName = GenVarName();

        var funcDefinition = LookupFuncSignature(funcCall.Namespace, funcCall.Name, funcCall.Parameters.Select(p => p.Type).ToList());
        if (funcDefinition == null)
        {
            throw new Exception($"Unknown function {funcCall}");
        }

        var parameterStrings = new List<string>();

        for (var i = 0; i < funcCall.Parameters.Count; i++)
        {
            if (i < funcDefinition.Parameters.Count && funcDefinition.Parameters[i].Variadic)
            {
                parameterStrings.Add("...");
            }

            NubType expectedType;
            if (i < funcDefinition.Parameters.Count)
            {
                expectedType = funcDefinition.Parameters[i].Type;
            }
            else if (funcDefinition.Parameters[^1].Variadic)
            {
                expectedType = funcDefinition.Parameters[^1].Type;
            }
            else
            {
                throw new Exception($"Parameters for func {funcCall} does not not match");
            }

            var parameter = funcCall.Parameters[i];
            var result = GenerateExpression(parameter);

            var qbeParameterType = SQT(expectedType.Equals(NubPrimitiveType.Any) ? parameter.Type : expectedType);
            parameterStrings.Add($"{qbeParameterType} {result}");
        }

        var funcName = _funcNames[funcDefinition];

        var call = $"call ${funcName}({string.Join(", ", parameterStrings)})";

        _builder.AppendLine($"    %{outputName} ={SQT(funcCall.Type)} {call}");
        return $"%{outputName}";
    }

    private string GenVarName()
    {
        return $"v{++_variableIndex}";
    }

    private string GenFuncName()
    {
        return $"f{++_funcIndex}";
    }

    private string GenLabelName()
    {
        return $"l{++_labelIndex}";
    }

    private IFuncSignature LookupFuncSignature(string @namespace, string name, List<NubType> parameters)
    {
        return _sourceFiles
            .Where(f => f.Namespace == @namespace)
            .SelectMany(f => f.Definitions)
            .OfType<IFuncSignature>()
            .Single(f => f.SignatureMatches(name, parameters));
    }

    private StructDefinitionNode LookupStructDefinition(string @namespace, string name)
    {
        return _sourceFiles
            .Where(f => f.Namespace == @namespace)
            .SelectMany(f => f.Definitions)
            .OfType<StructDefinitionNode>()
            .Single(s => s.Name == name);
    }

    private int LookupMemberOffset(StructDefinitionNode structDefinition, string member)
    {
        return structDefinition.Fields.TakeWhile(f => f.Name != member).Sum(f => QbeTypeSize(f.Type));
    }

    private class Variable
    {
        public required string Pointer { get; init; }
        public required NubType Type { get; init; }
    }
}